The present invention relates to a cassette loading apparatus for digital audio tape recorder (DAT), specifically relates to a cassette front loading apparatus for a DAT with a tray type loading by moving a cassette horizontally and vertically.
A conventional DAT is formed such that a tape cassette contained with an audio tape is positioned on reel tables within an interior of the apparatus, a tape is drawn out of a cassette and applied to a rotary head drum, thereafter a tape is driven to run by a driving force of a capstan motor, thereby record and reproduction of the tape can be executed. In such a DAT, a practical form of a conventional cassette front loading apparatus for moving a tape cassette from the exterior to the interior of an apparatus will be explained in detail in accordance with FIGS. 1 to 3 as follows.
In the drawings, the reference numeral 1 is a base plate, 2 is a cassette tray moving reciprocally and linearly against the base plate 1, 3 is a cassette holder which carries a DAT cassette 70 (refer to FIGS. 4 and 5) by moving with the tray 2, 4 is a loading motor for loading the cassette tray 2 and the cassette holder 3, 5 is a cassette lift and drop motor which moves downwardly as much as a predetermined length successively from the state that the cassette holder 3 is finished the horizontal movement, 6 is a slider opening plate which opens a slider 74 of a cassette 70, 7 is a push lever which properly and safely sets said cassette 70 into the cassette holder 3 in case of loading a cassette 70, 8 is a take out level which takes out said cassette 70 from the cassette holder 3 in case of loading a cassette 70, 9 is a driving gear which transfer the driving force of the cassette lift and drop motor 5, 10 is an opening operation plate which actuates the slider opening plate 6 by being coupled with said driving gear 9, and 11 represents a lift and drop operation plate which drops the cassette holder and the cassette 70 by being coupled with said driving gear 9, respectively.
To said base plate 1 are fixed tightly with guide bars 12 at the side edge portion, to both side plates 13 of said cassette tray 2 are arranged with linear bearings 14 which the guide bars 12 are inserted so that a cassette tray 2 moves linearly riding along the guide bars 12.
to the side plates 15 of said cassette holder 3 are movably connected respectively with the rotation levers 16 by connecting pieces 17 and each rotation levers are rotatably fixed at the both side plate 13 of the cassette tray 2 by axial pins 18, to the axial pins 18 there are fixed with torsion springs 19 supporting resiliently the rotation levers 16 in clockwise.
Aforesaid loading motor 4 is fixed to the base plate 1, at the bottom of the base plate 1 there are fixed with a pulley 22 which is connected to a pulley 21 with a pulley 20 fixed to a shaft of the loading motor 4, a gear 24 connected to a gear 23 formed integrally therewith, a pulley 25' connected by a wire 26 to a pulley 25 formed integrally therewith, and said wire 26 is connected with connecting pieces 27 fixed to said cassette tray 2. Therefore, the cassette tray 2, cassette holder 3, rotation lever 16 and take out lever 8 can be moved together linearly.
Aforesaid lift and drop motor 5, to which shaft a pulley 28 is fixed, is connected to a pulley 30 formed integrally with a worm 29 by a belt 31, and the worm 29 is meshed with the driving gear 9. At the lower surface of the driving gear 9, a small gear having a cam groove 33 at the peripheral surface thereof is integrally formed and is meshed with a rack 34 formed at a side edge portion of said lift and drop operation plate 11. At the lower portion of the driving gear 9, a cam lever 36 is rotatably mounted with a shaft pin 35 and a cam pin 37 provided on the upper surface of the cam lever 36 is inserted into the cam groove 33 of the driving gear 9 and, at the same time, another cam pin 37' is inserted into a rectangular guide hole 39 of said opening operation plate 10 through a pierced hole 38 formed at the base plate 1, and the cam lever 36 and the opening operation plate 10 are connected by a tension spring 40.
To said opening operation plate 10 is connected with said slider opening plate 6 by a shaft 41, said slider opening plate 6 and the opening operation plate 10 are connected with a tension spring 42, and the slider opening plate 6 is formed with a cassette hooking piece 43 at a front end portion and a contacting piece 44 is formed at rear portion, thereby the contacting piece 44 is allowed to couple with contacting to a 2-stage cam step portion 45 having an inclined plane of said lift and drop operation plate 11.
At a side of the lift and drop operation plate 11 of said base plate 1 there is fixed with a rotation relay lever 46 by a shaft 48 at a supporting piece 47 protruded from the base plate 1, at the same time it is urged by a tension spring 49, in case of the frontward moving of the lift and drop operation plate 11, it is formed such that it is pushed by its protrusion 50 and accordingly with rotating, it renders to rotate said rotation lever 16.
Aforesaid push lever 7 is formed such that when said cassette tray 2 is loaded, it rotates with contacting to a contact plate 51 which is formed by being bent downwardly at a frontward portion of the base plate 1, and it is allowed to rotate a push bar 52 through the gear and the coupling movement mechanism of the cam.
Aforesaid cassette take out lever 8 is fixed by a shaft pin 54 at a supporting plate 53 fixed between both side plates 13, 13 of the cassette tray 2, said take out lever 8 and the supporting plate 53 is connected with a tension spring 55 which urges the take out lever 8 in counter clockwise resiliently, and it is formed such that an inclined cam 56 is fixed at predetermined portion of the base plate 1 so that the take out plate 8 is slided.
Aforesaid loading motor 4 and cassette lift and drop motor 5, whose rotating direction or whether to stop or not etc. are determined in accordance with the combination of ON.OFF signals of the first, second, third and fourth location detecting switches 61, 62, 63, 64 fixed respectively at a predetermined location of the base plate 1.
FIGS. 4 and 5 show a DAT cassette, as shown in the drawings, a tape cassette 70 is established such that a slider 74 can be opened and closed in sliding manner to a main body 73 which a magnetic tape 71 is wound at reels 72 and contained therein, the reel hub exposing holes 75 are formed on the both sides at a main body 73, to a slider 74 is formed with a pierced hole 76 which is corresponded to the reel hub exposing hole 75 of the main body 73 in case of opening, and at both sides of the pierced hole 76 is formed respectively with a guide hole 77 which the release protrusion 57 of said cassette holder 3 is inserted, at the same time to the guide holes 77 of both sides is formed respectively at front portion with a lock hole 79 which a locker 73 protruded from the interior of the main body 73, a protect cover 80 is coupled by a hinge to the main body 73, to which protect cover 80 there is formed with a groove 81 which the hooking piece 58 of said cassette holder 3 is inserted.
A DAT cassette like this, is loaded and unloaded into the interior of DAT by said front loading apparatus, the loading operation is executed by a step which it is carried on the cassette holder 3 and moved as long as predetermined distance into the interior of the apparatus and by a step which it is moved vertically and set safely and properly to the reel table mounted at the base plate 1, the slider 74 is opened in time of horizontal movement and the protecting cover 80 is opened in time of vertical movement.
Hereinbelow, explaining more specifically the loading and unloading operation of a cassette in accordance with the conventional cassette front loading apparatus as described hereinbefore as follows.
FIGS. 1, 2 and 3A show the state that a cassette tray is ejected, at this moment a protrusion 59 of the connecting piece 27 fixed at a cassette tray 2 is contacted to a first location detecting switch 61 and becomes ON and the loading motor 4 is stopped.
In this condition, a cassette 70 is put in a cassette tray 2 and when the cassette tray 2 is slightly pushed into the innerward (into the rearward), the first location detecting switch 61 becomes OFF and the loading motor 4 rotates positively, with that power the cassette tray 2 together with the cassette holder 3 and the cassette 70 are pushed into innerward, the push bar 52 moves from the guide hole 60 of the cassette tray 2 trough the gear and the coupling movement mechanism of the lever in accordance with the push lever 7 being contacted to the contact plate 51 and then rotated, the cassette 70 is pushed by push bar 52 and is slightly moved inwardly and the release protrusion 57 of the cassette holder 3 is inserted to its guide groove 77 and the lock of slider 74 is released, at the same time the hooking piece 58 is inserted to the inserting hole 81 to which hooking piece 58 the front edge portion of slider 81 is hooked up, and it is supported stably by which the top surface is pressed with the rubber pressing roller 65 fixed adjacent to the connecting piece 15 of cassette holder 3. After the cassette 70 is set stably to the cassette holder 3 in this condition the cassette tray 2, cassette holder 3 and cassette 70 are moved continuously to inward by the driving power of the loading motor 4, when the protrusion 66' formed at a side plate 13 of cassette tray 2 actuate the second location detecting switch 62 and becomes ON then the loading motor 4 is stopped and the horizontal movement of the cassette tray 2 is completed, subsequently the cassette lift and drop motor 5 is rotated and the worm 29 and driving gear 9 are rotated and then the lift and drop driving plate 11 meshed with the small gear 32 of the driving gear 9 is moved frontwardly and then its protruded piece 66 is left away from the third location detecting switch 63 and the third location switch 63 becomes OFF, in accordance to the lift and drop operation plate 11 being moved, the contact piece 44 of the slider opening plate 6 contacted to which cam step portion 45 is lifted up, and the slider opening plate 6 is rotated in counterclockwise (based on FIG. 1) around the shaft 41 and contacted to the top surface of the cassette 70, in accordance with the driving gear 9 being rotated continuously by the driving power of driving motor 5, the lift and drop plate 11 is kept moving frontwardly at the same time the opening operation plate 10 is moved rearwardly by the operation of the cam lever 36 and the cam groove 33 of the bottom surface of driving gear 9 and the slider opening plate 6 are moved together rearwardly, thus the slider opening plate is moved, and whose hooking piece 43 hooks the cassette main body 73 and moves, therefor the cassette main body 73 is moved together, at this moment the slider 74 is hooked to the cassette holder 3 and the movement is stopped according to the slider 74 being opened and hose pierced hole 76 and the reel hub exposing hole 57 of main body 73 being coincided each other.
Thereafter, in accordance to the driving gear being kept rotating, the cam lever 36 cooperatively moving along with the cam groove 33, whose pin 37 is contacted to the concentric circle portion of the cam groove 33 and the rotation is stopped at the same time, accordingly the opening operation plate 10 and the slider opening plate 6 also are stopped, but the lift and drop plate 11 is allowed to keep moving frontwardly as in FIG. 3B, the protrusion 50 of which lift and drop plate 11 makes to rotate the rotation relay lever 46, in accordance to the rotation relay lever 16 being made the rotation lever 16 to rotate, the cassette holder 3 connected thereto is moved downwardly and vertically and is set stably on the reel table coupled to the predetermined portion of the base plate 1, at this moment the protrusion 67 protruded at the lift and drop plate 11 actuates the fourth location detecting switch 64 then the cassette left and drop motor 5 is made to stop.
In the above described process, summarizing the operation of the location detecting switches, if the state that the first to fourth location detecting switches 61-64 are depressed is supposed to be ON, in case of ejecting when the first location detecting switch 61 is ON then the loading motor 4 and the lift and drop motor 5 is got to stop; when the first location detecting switch 61 is OFF and the third location detecting switch 63 is ON then the loading motor 4 is got to positively rotate and continues to rotate until the second location detecting switch 62 becomes ON; when the second location detecting switch 62 becomes ON in the state that the third location detecting switch 63 is ON then the loading motor 4 is got to stop and the lift and drop motor 5 is rotated positively and the cassette 70 is got to set on the reel tables. When the cassette is set then the fourth location detecting switch 64 becomes ON by the protrusion 67 of the lift and drop operation plate 11 and the lift and drop motor 5 is got to stop and becomes to recognize the state of the cassette 70 being set.
Within the state that the cassette 70 is set on the reel tables, the tape 71 contained in the cassette 70 is drawn by the tape running mechanism and is applied to a rotary head drum and getting it to run by the driving power of the capstan motor, the recording or reproducing is executed (the rotary head drum, capstan motor and tape running mechanism are not shown in drawings).
After the play and record are executed as described above, in case when it is intended to eject, it is executed by the reverse operation procedure of abovementioned operation procedure, which is composed of such that when the cassette tray 2 is moved frontwardly and horizontally, the contact piece 68 of the take out lever 8 connected thereof is contacted to the inclined cam 56 fixed to the base plate 1 and is rotated in clockwise around the shaft pin 54, and the cassette 70 which the take out piece 69 is adhered with pressure to the cassette holder 3 by the rubber pressure roller 65 is pushed out slightly to forward so that a user can easily take out the cassette 70.
Since a conventional DAT front loading apparatus as described above uses the loading motor in order to move horizontally the cassette holder and cassette, and it uses the lift and drop motor in order to move vertically the cassette holder and cassette, accordingly both of the loading and unloading motors are required for loading and unloading of the cassette, and since it is formed with very much complicated structure that a device for setting stably the cassette at the cassette holder, a device for moving the cassette horizontally, a device for opening the slider, a device for lifting and dropping the cassette, a take out device for taking out so as to take out the cassette easily from the cassette holder, and the location detecting switch device, since all of these are requiring so many parts, there are the disadvantages that a productivity is decreased and the manufacturing cost is increased.